Alexander J. Kallen, MD, MPH, is a medical epidemiologist and outbreak response coordinator in the Division of Healthcare Quality Promotion at the Centers for Disease Control and Prevention (CDC). Dr. Kallen is also a volunteer attending physician in both the HIV clinic and infectious disease inpatient service at the Atlanta Veteran’s Affairs Medical Center. He has been with CDC since 2006, when he began serving as an Epidemic Intelligence Service (EIS) Officer. Dr. Kallen has published a plethora of peer-reviewed publications and abstracts on various topics including healthcare-associated invasive MRSA infections, multidrug-resistant gram-negative bacilli, infection prevention among hemodialysis patients, and the prevention of bloodstream infections. He is a journal reviewer for many journals including the Annals of Internal Medicine, Emerging Infectious Diseases, and the American Journal of Kidney Disease. Dr. Kallen is a member of the guideline committee for the Society for Healthcare Epidemiology of America (SHEA).